Insulating-bushing.



(7., H. THORDARSON. INsULATING BUSHING.

APPLIGATION FILED JAN. 29, 1910.

962,726. Patented June 28, 1910.

UNITED STATES FFTQE.

CHESTER H. THORDARSON, OF CHICAGO, ILLINOIS.

INSULATING-BUSHING.

Application filed January 29, 1910.

To all whom it may concern:

Be it known that I, Cnnsrnn H. Tnonnan- SON, a citizen of the UnitedStates, and a resident of Chicago, in the county of Cook and State ofIllinois, have invented certain new and useful Improvements inInsulating- Bushlngs; and I do hereby declare that the following is afull, clear, and exact description thereof, reference being had to theaccompanying drawings, and to the characters of reference markedthereon, which form a part of this specification.

This invention relates to a novel insulating bushing for electric wiringfor insulatmg wires from walls, plates and the like through which thewires extend, and to means for fastening such a bushing or othergenerally similar body or receptacle (as an electric lamp socket) to asupport through which it extends.

The invention refers more specifically to an insulating bushing or otherpart which is adapted to extend through an opening in a wall or plate orother part on which it is supported, and provided with means forremovably clamping or fastening the same to the wall, plate or otherpart. The body of such bushings, sockets and the like may ap provably bemade of porcelain or like vitreous material, and it is the purpose of myinvention to provide means for fastening the same in place of such anature as will avoid the forming of a screw thread on the insulatingbody, and also which will avoid strain, due to the clamping pressure ofthe screwthreads, being transmitted to the insulating body in a mannertending to break the same.

The invention is herein shown as applied to an insulating bushing forelectric wires, but it may be equally well applied to lamp sockets whichproject through openings in their supports and other generally similardevices which are arranged to be fastened in place in a generallysimilar manner to that herein shown.

The invention consists in the matters hereinafter set forth and moreparticularly pointed out in the appended claims.

In the drawings, Figure 1 is a side elevation of a bushing embodying myinvention, showing the same as mounted on a plate or support throughwhich it extends. Fig. 2 is an axial section thereof. Fig. 3 is an axialsection of the bushing body and the split screw threaded sleeve mountedthereon. Fig. t is an elevation of the insulating busl1 Specification ofLetters Patent.

ttnllriltii Patented June 28, 1910.

Serial No. 540,756.

ing body. Fig. 5 is an elevation of the split screw-threaded sleeveconstituting part of the fastening means. Fig. 6 is an elevation of ascrew-threaded locking nut. Fig. 7 is an end view of the parts, asassembled in Fig. 3.

As shown in said drawings, 10 designates the tubular bushing body madeof any suitable insulating material, such for instance as porcelain. Thesaid bushing body is provided at one end with a head 11, which ispreferably formed with a roughened periphery to aid in holding the samewhen the screw-threaded locking means are adjusted. The bushing isprovided at its end remote from the head with an annular shoulder 12,and the shank of the body is tapered inwardly from said shoulder towardthe head. The extreme end 1 1 of the body is made of the same diameteras near the head. The head is provided on its inner flat face, or thatadjacent to the shank, with one or more notches 15 for a purposehereinafter to be described, two diametrically opposite notches beingherein shown.

Surrounding the shank of the bushing is a spring metal sleeve 16, showndetached from other parts in Fig. 5. It is provided with an exteriorscrew thread which is adapted to receive a screw-threaded locking nut17, shown in place in Figs. 1 and 2 and detached from the other parts inFig. 6. The said sleeve 16 is made of a suitable spring metal,preferably sheet metal, and is pro vided at its inner end with a flange18 that fits on the flat inner face of the head of the bushing body. Theflange 18 is provided with lugs 19, 19 adapted to lit into the notches15 of the head to hold the sleeve non-rotative on the bushing body.These lugs may be formed in the flange 18 by crimping the same outwardlyin the manner clearly indicated in Fig. 1. The sleeve is adapted toslide freely on the shank of the bushing body when assembling the parts,the shank being made exteriorly smooth. The sleeve is longitudinallysplit as shown at 20, 20, so that it may be contracted inwardly againstthe shank.

The length of the sleeve is such that when in place the outer endthereof is just inside the plane of the shoulder 12 of the bushing body.Nhen the sleeve is contracted, there fore, on the shank the end of thesleeve is pressed downwardly behind said shoulder 12, as more clearlyindicated in Fig. 2,

whereby the sleeve is locked from axial movement on the shank of thebushing body. The split, spring sleeve is thus contracted by screwingthe locking nut 17 thereover. As herein shown the screw thread is madesomewhat deeper at the outer end of the sleeve than at the inner endthereof, so that when the cylindric screw thread locking nut 17 isscrew-threaded over the sleeve, the sleeve is compressed inwardly tobring the end of the same behind the shoulder 12, as stated. The saidshoulder, cooperating with the end of the sleeve as described, serves tolock the sleeve from endwise movement on the bushing body, so that thescrew thread carried by the metal sleeve becomes a fixed part of thebushing body. lVhen the split sleeve is unconfined by the nut 17, theresilient members between the slits 20 spring outwardly as shown in Fig.3 so that the sleeve may be passed freely upon and slipped off the body.

The split spring sleeve is herein shown as made of special constructionto provide the exterior screw thread thereon. As herein illustrated thesleeve is made of a piece of metal substantially twice as long as thefinal length of the sleeve, and the outer ends 21 of the portionsthereof between the slits 20 are turned backwardly upon the portions 22of the sleeve next adjacent the flange; and it is upon the backwardlyturned members 21 that the screw thread is formed. This ararrangementprovides for the required thickness of the threaded portion of thesleeve to permit the proper engagement therewith of the screw-threadedlocking nut 17 to contract the split sleeve with its end inwardly behindshoulder 12. So far as the broader features of the invention areconcerned, however, said sleeve, or its equivalent part may be otherwisemade.

The locking nut 17 may be made of sheet metal and preferably of a metalpossessing some spring or resiliency. It is provided at its inner endwith an annular radial flange 23 which opposes, and is adapted tocooperate with the head of the bushing body to clamp the bushing bodyupon the support 1or plate confined between said flange and lead.

In assembling the parts of the bushing, the contractible, screw-threadedsleeve is first slipped endwise over the shank of the bushing body andthe lugs 19 are engaged with the notches 15 of the head. Thereafter thesplit outer end of the screw-threaded sleeve 16 is pressed inwardly bythe fingers, and the locking nut 17 is screw-threaded over the sleeveand contracts the split sleeve to bring its end behind the retainingshoulder 12. In this position of the parts it will be obvious that thescrew-threaded sleeve is retained fixedly n the bushing body, so long asthe nut IS in place, and that the device may be handled as an article ofmanufacture without danger of the parts becoming detached and lost. Thebushing is applied to the part which supports it by removing the lockingnut and inserting the shank through an opening in said support with thehead of the body bearing against one slde of the support; the inner sideof the head or the flange engaged therewith constituting a shoulder orabutment that cooperates with the flange of the locking nut to clamp thebushing in place. The nut is then applied to the screwthreaded, splitsleeve and turned up against the side of the support opposite to thehead so as to clamp the device in place with the support confinedbetween said head and the flange of the locking nut.

An important advantage of the construction described is that the strainor stress due to the screw thread action of the nut 17 to clamp thebushing or other part in place is transmitted directly to and isreceived wholly by the screw-threaded sleeve 16, and no part of thestrain or stress is brought upon the insulating body itself. This is ofspecial importance when the body is made of porcelain or like relativelyfragile material, inasmuch as it has been found that the stress of thescrew-threaded clamping pressure tends to and does in many instancesbreak the body. The breaking of the body obviously seriously or entirelyimpairs the insulating efficiency of the device. Another advantage ofthe construction described is that the casting of a screw thread on theinsulating body is thereby avoided. The casting of a screw thread onporcelain or like substances is a source of considerable annoyance andexpense and I have found it to be less expensive to apply thecollapsible screw-threaded sleeve to the body than to cast the threadintegrally therewith.

The bushing or other body, and screwthreaded sleeve 16 thereon, such asis shown in Fig. 3, may be screwed into a screwthreaded socket of arelatively heavy part that supports the same, as for instance in asocket formed in the casting of an electrical machine. The engagement ofthe screwthreaded contractible sleeve 16 with the screw-threaded socketwall serves to contract the sleeve on the insulating body in the samemanner as does the nut 17, and thereby lock the sleeve in place on saidbody.

It will be understood that the details of the construction illustratedmay be consid erably varied within the scope of my invention, and thatthe invention is not limited to such details except as hereinafter madesubject to specific claims.

I claim as my invention:

1. An insulating bushing for electric wiring comprising a headed,tubular, insulating body, a screwthreaded sleeve removably fitted to thebody and having means for locking it from endwise and angular movementthereon, and a flanged screw-threaded looking nut engaged over saidsleeve and constituting part of the means for locking said sleeve onsaid body.

2. An insulating bushing for electric wir ing comprising a headedinsulating body, a split, screw-threaded sleeve adapted to be slippedendwise over the body and having means for locking it from rotationthereon and a flanged locking nut engaged over said sleeve andcooperating with means for locking the sleeve from endwise movement onthe insulating body.

3. An insulating bushing for electric wiring comprising a tubular shankprovided at one end with an enlarged head and at its other end with anarrow shoulder, a split, screw-threaded sleeve removably fitted overthe shank and having means for preventing it from turning thereon, and ascrewthreaded nut engaging over the screwthreaded sleeve and arranged topress the split end of the sleeve behind said shoulder to lock thesleeve from endwise movement on the shank.

4. An insulating bushing for electric wiring comprising a headed,tubular, insulating body, a split, screw-threaded sleeve removablyfitted over the body and provided with a flange having interlockingengagement with the head of the body, the body provided at its endremote from the head with a narrow shoulder adapted to be engaged by theend of said sleeve, and a screwthreaded locking nut engaged over saidsleeve and arranged to contract the split sleeve with its end behindsaid shoulder.

5. An insulating bushing for electric wiring comprising a tubular,insulating body provided at one end with an enlarged head and at itsother end with a shoulder, a split, screw-threaded sleeve removablyfitted over the body and provided at one end with a flange arranged tointerlock with said head and adapted to be contracted at its other endbehind said shoulder, and a screwthreaded locking nut engaging over thescrew-threaded sleeve to so contract the sleeve.

6. An insulating bushing for electric wiring comprising a tubular,insulating body provided at one end with a head and at its other endwith a shoulder and tapered from the head to the shoulder, a split,screwthreaded sleeve removably fitted over the body and interlocked fromrotation thereon and a screw thread locking nut for contracting thesleeve upon the tapered portion of the body, with its split end behindsaid shoulder to lock it from endwise movement on the body.

7. In combination, a body having at one end an enlarged head or shoulderand at its other end a narrower shoulder, a sleeve removably fittedthereover and having means for looking it from rotation thereon, thesleeve comprising a smooth inner "all portion and an outer wall, theouter wall being screw-threaded and the sleeve being longitudinallyslitted through both walls, and a. screw thread locking nut engagingover the screw-threaded sleeve and arranged to contract the split sleeveend behind said narrower shoulder.

8. In combination, a shouldered insulating body, a split sleeveremovably fitted thereover and having means for looking it from angularand endwise movement thereon, the sleeve comprising an inner portion andan outer portion, the latter consisting of the split end portions of thesleeve turned backwardly over the inner portion and provided with ascrew thread, and a screwthreaded locking nut engaged over the sleeve.

9. In combination, an insulating body having a portion adapted to extendthrough an opening in a support, a flanged, screwthreaded split sleeveremovably fitted on and interlocked to said body, and a screwthreadedlocking nut engaged over said sleeve and opposing the flange of thesleeve.

10. The combination with an insulating body having a shank portionadapted to extend through an opening in a support and having at one endan enlarged head or shoulder to bear against one side of the support,and at its other end a narrower shoulder, a split, screw-threaded sleeveremovably fitted over said shank and interlocked non-rotatively on thebody, and a screw-threaded locking nut engaged over said sleeve andarranged to contract the split end of the sleeve behind said shoulder tohold the sleeve from endwise movement on the body.

11. The combination with an insulating body having a shank portionadapted to extend through an opening in a support and having at one endan enlarged head or shoulder to bear against one side of the support,and at its other end a narrower shoulder, a split, screw-threaded sleeveremovably fitted over said shank and formed with a flange which fitsagainst and interlocks with said enlarged shoulder, and a screw-threadedlocking nut engaged over said sleeve and arranged to contract the splitend of the sleeve behind said narrower shoulder, and provided with aflange which opposes said sleeve flange.

12. The combination with an insulating body, of a contractible springscrew-threaded sleeve removably fitted thereto and arranged to be lockedon said body when screwed into a screw-threaded shell or socket.

13. The combination with an insulating body formed with an elongatedportion having at one end an enlarged shoulder and at as my invention Iaffix my signature in the lts other end a narrow shoulder, of a screW-presence of two Witnesses, this 26th day of 10 threaded contractlblespring sleeve reinov- January A. D. 1910.

ably fitted over said elon 'at-ed portion and T non-rotatively fittedthereto and adapted to CHESTER THORDARSO1\' be contracted With its endbehind said nar- \Vitnesses:

rower shoulder. WVILLIAM L. HALL,

In testimony that I claim the foregoing l VILLIAM GOLDBERGER.

